Recently, digital magnetic recording has been keenly studied, and system design and tape design therefor have been developed and become common. A characteristic feature of digital magnetic recording is that a higher image quality and a higher tone quality can be expected than those obtainable by conventional analog recording. Items to be selected in a system design include a recording method, a detection method, and an equalization. On the other hand, for tape design, it is important to determine how best to realize high density recording and to analyze the means to attain high density recording. The present invention relates to tape design and to a magnetic recording medium for attaining high density recording.
Different from a magnetic recording medium for analog recording, in a magnetic recording medium for digital recording, recording is made by binary system using 0 and 1. Thus, even though noises are interjected, the initial degital information can be firmly maintained. Therefore, digital recording is very effective against noise. However, as digital recording is made by binary system, errors easily occur upon recording and replaying. These errors in a magnetic recording medium are attributed to dropouts caused by tiny dust particles and contaminants adhered thereon, cross talk from an adjacent track, a prior recorded signal because of insufficient erasure, and printed-through signals. These errors are serious defects and impair the quality of the magnetic recording medium and should be completely avoided. Further, in a magnetic recording medium, tape running noise and head impedance noise and the like needs to be controlled. S/N (signal/noise) of replayed signals depends on bit distance, width of a recording track, coercive force of a tape, squareness ratio, and the like, and these depend on various system designs.